most users already dont use what theyve got. its more about reducing physical size for the masses… these new techs will allow for even smaller storage for thinner, more efficient devices.

i think only some power users (im a data horader) and commercial interests care about bulk storage

Thermal is a wall to contend with as well. At the moment SSDs get the density from 3D stacking the planes of substrate that make up the memory cells. Each layer contributes some heat and at some point the layer in the middle gets too hot from the layers below and not being close enough to the top to dissipate the heat upwards fast enough.

One way to address this was the multi-level cell (MLC) where instead of on/off, the voltage within the cell could represent multiple bits. So 0-1.5v = 00, 1.6-3v = 01, 3.1-4.5v = 10, 4.6-5v = 11. But that requires sense amplifiers that can handle that, which aren’t difficult outright to etch, they just add complexity to ensure that the amplifier read the correct value. We’ve since moved to eight-level cells, where each cell holds an entire byte, and the error correction circuits are wild for the sense amplifiers. But all NAND FGMOS leak, so if you pack eight levels into a single cell, even small leaks can be the difference between sensing one level from another level. So at some point packing more levels into the cell will just lead to a cell that leaks too quickly for the word “storage” to be applied to the device. It’s not really storage any longer if powering the device off for half a year puts all the data at risk.

So once going upwards and packing hits a wall, the next direction is moving out. But the more you move outward, the further one is placing the physical memory cells from the controller. It’s a non-zero amount of distance and the speed of light is only so fast. One light-nanosecond is about 300 millimetres, so a device operating at 1GHz frequency clock has that distance to cover in a single tick of the clock in an ideal situation, which heat, quantum effects, and so on all conspire to make it less than ideal. So you can only go so far out before you begin to require cache in the in-between steps and scheduling of block access that make the entire thing more complex and potentially slow it down.

And there are ways to get around that as well, but all of them begin to really increase the cost, like having multi-port chips that are accessed on multi-channel buses, basically creating a small network inside your SSD of chips. Sort of how like a lot of CPUs are starting to swap over to chiplet designs. We can absolutely keep going, but there’s going to be cost associated with that “keep going” that’s going to be hard to bring down. So there will be a point where that “cost to utility” equation for end-users will start playing a much larger role long before we hit some physical wall.

That said, the 200 domain of layers was thought to be the wall for stacking due to heat, there was some creative work done and the number of layers got past 300, but the chips do indeed generate a lot more heat these days. And maybe heat sinks and fans for your SSD aren’t too far off in the future, I know passive cooling with a heat sink is already becoming vogue with SSDs. The article indicated that Samsung and SK hynix predict being able to hit 1000+ layers, which that’s crazy to think about, because even with the tricks being employed today to help get heat out of the middle layers faster, I don’t see how we use those same tricks to hit past 500+ layers without a major change in production of the cells, which usually there’s a lot of R&D that goes behind such a thing. So maybe they’ve been working on something nobody else knows about, or maybe they’re going to have active cooling for SSDs? Who knows, but 1000+ layers is wild to think about, but I’m pretty sure that such chips are not going to come down in prices as quickly as some consumers might hope. As it gets more complex, that length of time before prices start to go down starts to increase. And that slows overall demand for more density as only the ones who see the higher cost being worth their specific need gets more limited to very niche applications.

We hit that point in spinning disk drives a while ago for me

The issue is, every time we make a great leap in storage medium, we tend to use that new storage for BIGGER files. Higher quality media and all that. Back in the day, the average movie file was measured in the MB. Now it’s GB. Think about an old floppy with 1.4 MB of data and how many text files you stored on it. You couldn’t ever imagine needing more space. Then came pictures and music files. Video files. Then higher resolution picture and video files. Suddenly even your text documents aren’t just raw .txt files, but Word documents and interactive PDFs.

As storage improves, what we expect to be able to carry around with us or have in our home computer changes. I’m currently running a home server with 18TB of storage. An amount that I would have never dreamed of possessing 20 years ago, and yet here I am debating when I grab that 24TB drive because I can already see me running out of space in a few months.

This is all to say that I really don’t think there will ever be a maximum amount a user could need. Give them that maximum and in a week they’ll have figured out a way to use it to capacity. I think video games and cartridge/disk size limitations and then the transition to digital games and balloning game size shows my point.

Its already been 6 years since the first 100TB SSD released and I still don’t think anyone has bothered to dethrone it last I checked. Density and number of layers possible have both increased since then. I imagine part of it is just a performance issue though; 10 10TB SSDs are gonna be faster than 1 100TB SSD.

At the consumer level, the usage of smaller form factors will probably mean more density will still be useful. Things like the steamdeck drives will benefit for a while.

They’ll be useful for gamers, at least. With the increasing trend of companies caring less about properly optimizing the size of game installs and expecting gamers to have SSDs for texture loading on the fly, these drives will definitely see use. I currently have a 4TB HDD that has over 2.3TB of Steam games installed on it right now (roughly 100 games from tiny indie games to big AAA releases that are 40-80 gigs in size), and several newer games have an SSD listed as one of their minimum requirements.

NAND density is always useful for the ultra portable end, be it used in applications like phones, portable gaming devices, microcontroller boards and such, where space or pci-e lanes is often the limiting factor. when the capacity of nand grows, options become better, as nand usually doubles in capacity per chip.

We’ve already hit a perceived user experience limit. The perception of responsiveness in blind tests between SATA and NVMe SSDs isn’t always apparent–people sometimes say the SATA drive is faster–even though the speed difference on paper is substantial.

IMO, programmers haven’t exploited the possibilities of extremely fast mass storage yet. The orders of magnitude difference in speed isn’t fully realized. It’s not just faster, it’s faster in a way that requires new approaches. Unlike multicore CPUs over a decade ago, this change in thinking has gone relatively unnoticed by programmers.